Protein chips types

Protein Chips Proteins, too, can be immobilized on a solid surface and used to help define the presence or absence of other proteins in a sample. For example, researchers prepare an array of antibodies to particular proteins by immobilizing them as individual spots on a solid surface. A sample of proteins is added, and if the protein that binds any of the antibodies is present in the sample, it can be detected by a solid-state form of the ELISA assay (see Fig. 5-28). Many other types and applications of protein chips are being developed. 

PPIs were discovered of which 12 were confirmed by co-expression analysis. The main advantage of the protein chips is to provide qnantitative estimation of the PPIs strength compared to the binary type of information provided by Y2H and co-affinity pnrification conpled to Mass Spectrometry procednres. 

A protein chip is a glass, plastic or silicon chip onto which different proteins have been attached at separate locations in an ordered manner to form a microscopic array. They are attached mainly by adsorption, absorption, covalent cross-linking or affinity binding. There are two main types of protein arrays analytical arrays and functional protein arrays. In the hrst type the capture molecules are antibodies or antibody mimics which are used to detect the presence and amount of protein in a sample. These are mainly used for diagnostics and expression profiling experiments. The second type of protein array involves immobilising proteins on a chip and using the chip to probe biochemical activity. 

The most common type of capture molecules used on a protein chip are antibodies, though other proteins, such as peptides, nucleic acids, enzymes and receptors, have been spotted on to chips. Protein chips can be difficult to prepare, as the proteins need to be kept in an active state, in a high concentration and in a moist environment. Typical samples investigated are cell lysates for general research or blood and urine for diagnostic applications. Fluorescence detection methods are preferred since they are simple and sensitive. Other detection methods, where labelling is not required, can take the form of SELDl or AFM. 

Emerging applications of PC include inhalers for the consumer market, ophthalmic products, orthopaedic materials, and lab-on-a-chip type of devices to determine blood chemistry/or to analyse proteins. 

Protein chips are miniature devices on which proteins, or reagents that capture proteins from solution, are applied in an array. There are many different types of protein chip, some used to analyze protein abundance and others used to study protein functions. 

This emerging technology has the potential to considerably improve the throughput of protein analysis, particularly with the recent advent of a whole pro-teome chip for the yeast Saccharomyces cerevisiae. The various different types of protein chip that have been described are summarized below ... 

In another study that evaluated the protein fingerprints of HIV-1-infected MDM, cell lysates were directly applied on two types of protein chips weak cation exchange and reverse-phase hydrophobic interaction. After washing to remove the unbound proteins, bound proteins were ionized and their molecular mass/charge ratio was determined using TOP analysis. Analysis of the obtained profiles showed distinct patterns between uninfected and infected MDM [33]. 

Figure 29. Setip of a chip type SERS device combining well defined and highly reproducible gold colloids with the high amplification factor of silver-cluster surfaces using a HEME-protein for energy transfer.

A developing application of DNA technology uses a DNA chip that contains many small segments of bases of known sequence. Such DNA chips are being used to attack cancers. Cancers occur when defective genes cause cells to divide uncontrollably, but usually the process of protein synthesis also is modified. Different types of cancer result in different modifications to protein synthesis, depending on how the DNA... 

Currently, protein microarrays can be divided into various types depending on the strategies to be chosen. For example, according to the array structure and shape, protein microarrays include 3D-surface structure [30, 31], nanowell [32], and plain chips [33-36], Meanwhile, considering the field of application, protein microarrays can be classified into five categories antibody array, antigen or reserve array, functional array, capture array, and solute array. Table 11.6 shows the differences among them. 

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